> A preprocessing directive of the form > # include < h-char-sequence> new-line > searches a sequence of implementation-defined places for a header identified ....
> 3 A preprocessing directive of the form > # include " q-char-sequence" new-line > causes the replacement of that directive by the entire contents of the source file identified...
> [Note: (略) in general programmers should use > the < > form for headers provided with the implementation, > and the " " form for sources outside the control of the implementation.
